Factory fabricated buildings intended to be erected, or assembled, on the building site are well known and include the modular type, the sectional type and the pre-fab panel type.
It has heretofore been proposed to provide conventional buildings with concrete wall panels of uniform cross section supported by vertical steel I-beams both supported on a conventional above ground foundation, as in U.S. Pat. No. 1,858,701 to Boettcher of May 17, 1932, both supported on a subground level footing, as in U.S. Pat. Nos. 3,216,156 and 3,216,163 to Carew of Nov. 9, 1965. However, the panels of these patents are not of U-cross section with load bearing side flanges and they are more like curtain walls hung from the steel structure.
It has also been proposed to provide wall panels of a waffle or grid-like pattern, with no integral reinforced load bearing columns, and resting on a ground level slab, as in U.S. Pat. 2,184,464 to Myers of Dec. 26, 1939, U.S. Pat. 2,497,887 to Hilpert of Feb. 21, 1950, or U.S. Pat. 2,811,850 to Clary of Nov. 5, 1967. None of the panels of these patents are of U-cross section, none include an integral foundation wall portion extending below ground level to a footing and all rely on rib and groove vertical joints for sealing the edges of adjacent panels.
In Belgian patent No. 517,689 to Van Wetter of Feb. 28, 1953, spaced, concrete channels, or arched beams, horizontally span a roof and are of inverted U-shaped cross section. Horizontal panels are supported on ledges in grooves in the channels but the channels serve only to resist tension forces. There are no vertical wall panels in this patent capable of resisting compressive forces, or being mounted endwise one on the other to any desired height.